Octahedral Geometry Research Articles

Fabrication, physicochemical characterization and theoretical studies of some new mixed ligands complexes based on N-(1H-benzimidazol-2-yl)-guanidine and 1, 10-phenanthroline: DNA interaction, biological applications and molecular docking approach

The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with Kf values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H2O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC50% are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent.

Bio‐evaluation of pyrazolone‐furan derived Schiff base Cr(III), Co(II), Ni(II), Cu(II), and Zn(II) nano‐sized complexes: Design, spectral characterization, antimicrobial efficacy, antioxidant activity, apoptotic activity, and cell cycle analysis

A tridentate pyrazolone‐furan Schiff's base ligand, [(E)‐4‐(((5‐[2‐fluorophenyl]furan‐2‐yl)methylene)amino)‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one] (PFSB), was produced by condensation between compounds 5‐(2‐fluorophenyl)furan‐2‐carbaldehyde and 4‐amino‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one. Spectroscopic characterization evidence suggested the tridentate nature (ONO) of pyrazolone‐furan Schiff's base ligand (PFSB) and coordinated to the metal (II/III) moieties through nitrogen and oxygen donor sites giving tetra‐ and/or hexa‐coordinated geometry to complexes. The complexes have been supported by elemental analyses, molar conductance, magnetic moments, spectral analyses, EPR, ligand field parameters, XRD, and thermogravimetric measurements. Theoretical optimization employing the density functional theory (DFT) was accomplished on the molecular structures of the compounds in question, and subsequently, the quantum chemical descriptors were computed. Cr(III), Co(II), Ni(II), and Zn(II) complexes were allocated octahedral coordination, while the Cu(II) complex was allocated square‐planar coordination. The SEM, TEM, XRD, AFM, and EDX of the studied complexes unveiled distinct and strong diffraction peaks, signifying their crystalline nature, and providing evidence of their particle sizes being within the nano‐size. The crystal sizes calculated for all complexes were determined to be ranging from 27.73 to 76.39 nm. However, the Cr(III) complex exhibited a particle size exceeding 100 nm. The interactions between metal complexes and calf thymus DNA, and their potential for mimicking insulin activity, were investigated in a controlled lab setting by measuring their ability to inhibit alpha‐amylase. The anti‐microbial potential of the ligand (PFSB) and complexes (C1‐C5) were tested. The viscosity and UV–Vis absorption determinations were utilized to assess the calf thymus DNA (CT‐DNA) interaction with the nano‐sized metal (II/III) chelates. Our flow cytometry data indicate significant levels of apoptosis and cell cycle arresting in both liver and breast cancer cell lines.

The Co‐UMO‐1 Metal Organic Framework: Solvothermal Synthesis of [Co3{μ3‐O}2(C14H8O6S)2(H2O)3(C2H5OH)] ⋅ 2H2O, Characterizations, and Application in Methylene Blue Removal

AbstractThe new Co‐based MOF (also called Co‐UMO‐1 MOF with structure of [Co3{μ3‐O}2(C14H8O6S)2(H2O)3(C2H5OH)] ⋅ 2H2O) is solvothermally synthesized in a mixture of water and ethanol at 170 °C for 3 days. The as‐recovered pink‐colored stick‐like crystals crystallizes in the monoclinic crystal system P21/c (n° 13), which consists of three crystallographically independent Co(II) elements that adopt the octahedral coordination geometry. The MOF was also successfully characterized by FTIR, SEM, BET, Zeta potential and UV‐Vis spectroscopy, as well as TG and DSC analyses. At pH 7 and 25 °C, Co‐UMO‐1 MOF shows the maximum of its capacity of adsorption (31.5 mgr gr−1) of the methylene blue (MB) dye, which corresponds to an adsorption efficiency of 79 %. The adsorption of MB follows the pseudo‐second order kinetic model, and occurs via the formation of a monolayer onto the surface of the MOF, in line with the Langmuir isotherm model. Adsorption efficiencies higher than 79 % have not been achieved with Co‐UMO‐1 MOF because of electrostatic interactions between the MOF surface and the MB molecules, which has been confirmed by the Temkin isotherm model. In the aforementioned conditions, Co‐UMO‐1 MOF can be reused after regeneration, showing an adsorption efficiency of 76.2 % after five cycles, which is a promising result.

Well isolated copper(II) pyrazine-bridged chains: synthesis and magneto-structural analysis of 2-halo-4-pyridone perchlorate complexes

Two new coordination polymers, [Cu(pz)(L)2(H2O)2](ClO4)2 (L = 2-Cl- (1) or 2-Br-4-pyridone (2); pz = pyrazine), have been synthesized and characterized by X-ray diffraction, EPR and variable temperature magnetic measurements. Both compounds crystallize as well isolated pyrazine-bridged chains with the heterocyclic ligands in the pyridone tautomer and coordinated via the oxygen atom. The Cu ions possess Jahn-Teller elongated octahedral geometries with the Jahn-Teller axis along the Cu-O axis. The water molecules in 2 are inequivalent with one molecule semi-coordinate (dCu… O = 3.225(6) Å) at an occupancy of 0.72. Both compounds exhibited axial powder EPR spectra, as expected. Variable temperature magnetic measurements are well fit by the uniform chain Heisenberg antiferromagnetic model with J = −10.74(4) K (1) or = −10.64(2) K (2). Comparison with the known 3-halo-4-pyridone compounds suggests an inverse relationship between the Cu-pz-Cu distance and the strength of the magnetic exchange.

Development of cancer-targeted nano gold functionalized ruthenium(III)-doxorubicin complex: Synthesis, characterization and evaluation of DNA cleavage, anticancer and bioimaging activity

Metal-based drugs have attracted greater attention for cancer diseases because of biological relevance. However, some drawbacks are present in the metal complexes such as low stability and low bioavailability. Nanomaterials functionalized metal complexes can protect the stability and enhanced the bioavailability. In the present study, Nano gold functionalized ruthenium(III) complex from doxorubicin have been synthesized from ruthenium(III) complex and characterized using various spectrochemical techniques such as IR, UV, and NMR. In the metal complex, Doxorubicin (DOX) acts as a monobasic bidentate ligand and is coordinated through the carbonyl oxygen and phenolate oxygen of the anthracene ring. Based on spectral evidences, the complex [Ru(DOX)(PPh3)2Cl2] has an octahedral geometry. The Nano Au-Ru(III) DOX is analysed for their size, and morphology using XRD, SEM and HRTEM. X-ray diffraction pattern revealed that the complex has nanocrystalline in nature. The Nano Au-Ru(III) DOX is spherical shape and particle size is less than 15 nm. The DNA cleavage activity of [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX has been evaluated using pUC18 plasmid DNA and the results showed significant cleavage. The [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX have been tested against human breast cancer (MCF-7) and leukemia cancer cell lines (K-562) in vitro for its antitumor effects. The tumour activity of the Nano Au-Ru(III) DOX showed more promising activity than the [Ru(DOX)(PPh3)2Cl2]. The cell imaging of the Nano Au-Ru(III) DOX was examined against epithelial human breast cancer cell line (MDA-MB-231) using fluorescent microscopy. The fluorescence images showed high scattering light in tumour tissue at 100 µg/mL Hence, Nano Au-Ru(III) DOX can serve as a promising drug for cancer therapy and cellular imaging.

New nanometric metal complexes based on thiazole derivative as potential antitumor and antimicrobial agents: Full structural elucidation, docking simulation and biological activity studies

Novel Mn(II), Ni(II), Zr(IV) and Cd(II) nanosized complexes of thiazole Schiff base derivative (HL) were synthesized for further medicinal applications. The inspected complexes were fully characterized using elemental and thermal analyses in addition to infrared spectroscopy (IR) and nuclear magnetic resonance (1HNMR). Electronic absorption spectra, X-ray powder diffraction (XRD), transmittance electron microscopy (TEM), molar conductance and magnetic moment were also measured and explained. The brought about data revealed that the ligand–metal chelation happened through the N atom of N = N group, and the ortho-dehydrogenated phenolic O atom to form the chelates where the metal binds with one molecule of the parent ligand. All applied spectroscopic and analytical techniques confirmed tetrahedral geometry in Mn(II) and Ni(II) complexes and octahedral geometry for Cd(II) and Zr(IV) complexes. The ligand, Mn(II), Ni(II), and Zr(IV) chelates' XRD patterns indicated an amorphous character where the Cd(II) complex's nature is crystalline. Transmission electron microscopy (TEM) images of the prepared compounds showed that the surface morphology is uniform and homogeneous. Also, the metal ions distribute through the complexes' surface in a nanosized nature. The metal complexes have been simulated by docking in the co-crystal structures of the liver cancer and breast cancer proteins with PDB IDs, 2JW2 and 3S7S, successively. Antibacterial, antifungal and anticancer activities for the ligand that has been produced and its complexes were achieved. The most encouraging antitumor results were acquired by Ni(II) chelate which exhibited an IC50 of 23.52 µg/ml contra MCF-7 cells (human breast cancer) which is lower than the reference 5-Fluorouracil (5-FU, IC50 = 28.00 µg/ml).

Promoting the Anticancer Activity with Multidentate Furan-2-Carboxamide Functionalized Aroyl Thiourea Chelation in Binuclear Half-Sandwich Ruthenium(II) Complexes.

A new set of binuclear arene ruthenium complexes [Ru2(p-cymene)2(k4-N2OS)(L1-L3)Cl2] (Ru2L1-Ru2L3) encompassing furan-2-carboxamide-based aroylthiourea derivatives (H2L1-H2L3) was synthesized and characterized by various spectral and analytical techniques. Single-crystal XRD analysis unveils the N^O and N^S mixed monobasic bidentate coordination of the ligands constructing N, S, Cl/N, O, and Cl legged piano stool octahedral geometry. DFT analysis demonstrates the predilection for the formation of stable arene ruthenium complexes. In vitro antiproliferative activity of the complexes was examined against human cervical (HeLa), breast (MCF-7), and lung (A549) cancerous and noncancerous monkey kidney epithelial (Vero) cells. All the complexes are more efficacious against HeLa and MCF-7 cells with low inhibitory doses (3.86-11.02 μM). Specifically, Ru2L3 incorporating p-cymene and -OCH3 fragments exhibits high lipophilicity, significant cytotoxicity against cancer cells, and lower toxicity on noncancerous cells. Staining analysis indicates the apoptosis-associated cell morphological changes expressively in MCF-7 cells. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) analyses reveal that Ru2L3 can raise ROS levels, reduce MMP, and trigger mitochondrial dysfunction-mediated apoptosis. The catalytic oxidation of glutathione (GSH) to its disulfide form (GSSG) by the complexes may simultaneously increase the ROS levels, alluding to their observed cytotoxicity and apoptosis induction. Flow cytometry determined the quantitative classification of late apoptosis and S-phase arrest in MCF-7 and HeLa cells. Western blotting analysis confirmed that the complexes promote apoptosis by upregulating Caspase-3 and Caspase-9 and downregulating BCL-2. Molecular docking studies unfolded the strong binding affinities of the complexes with VEGFR2, an angiogenic signaling receptor, and BCL2, Cyclin D1, and HER2 proteins typically overexpressed on tumor cells.

Zn(II), Mn(III), and Co(III) complexes of Schiff base derived from 2‐hydroxy‐1‐naphthaldehyde: Synthesis, spectral surveys, single crystal structure studies, Hirshfeld surface analysis, density functional theory calculation, molecular electrostatic potential, and molecular docking evaluations

A new series of transition metal complexes of bidentate Schiff base compound derived from 2‐hydroxy‐1‐(2‐methoxyethylimino)‐naphthalene (HL) were synthesized and characterized using elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), and UV–vis spectroscopies. X‐ray single crystal structures of Zn(II), Mn(III), and Co(III) complexes (1–4) have also been determined, and it was indicated that these Zn(II) and Co(III) complexes (1, 4) are in an octahedral geometry. Whereas, it was found that the Zn complex (2) is in quite a regular tetrahedral environment. Also, the Mn center in complex (3) is ligated by two azomethine nitrogen atoms, two ligand oxygen atoms, and one Cl atom of metal salt forming five coordinated tetragonal pyramid geometry around the Mn atoms. The cyclic voltammetry of the complexes specifies an irreversible redox behavior for all complexes (1–4). Next, DFT/B3LYP theoretical method was used to determine the optimal geometrical configurations and comparison between experimental and theoretical data, as well as for calculations of molecular electrostatic potential, highest‐occupied molecular orbital (HOMO)‐lowest‐unoccupied molecular orbital (LUMO) energy values of selected compounds. The study of non‐covalent interactions was done by Hirshfeld surface analysis using CrystalExplorer program. Furthermore, molecular docking inspection was carried out to study the binding affinity of the tested complexes towards protein B‐cell lymphorna (PDB ID: 4LXD). Using the results obtained from the molecular docking and the summarized interaction of the binding processes, these structures show the validity of effective inhibition against liver cancer.

Linear and non-linear optical and dielectric properties of transition metals complexes films derived from Azo-Schiff base for photovoltaic applications

A novel azo-Schiff base, which incorporates a heterocyclic triazole nucleus known as 1H-1,2,4-triazol-5-yl)imino)methyl)-5-((2-nitrophenyl)diazenyl)phenol (H2ASB, 1), was formulated and synthesized. Furthermore, a series of Cu2+ complexes, derived from this azo-Schiff base, were prepared by a simple method with a molar ratio of 1 M Cu2+ to 1 M H2ASB. The synthesized compounds were thoroughly characterized using alternative analytical and spectral techniques. The obtained results confirmed that H2ASB bonded with the Cu2+ ions in a uni-negative/neutral bidentate manner, via the phenolic hydroxyl oxygen and azomethine nitrogen atom, thereby resulting in tetrahedral or octahedral geometries. Additionally, theoretical studies employing DFT/B3LYP/LanL2DZ were conducted, which included the assessment of global reactivity descriptors, dipole moment, molecular electrostatic potential image (MEP), optimized geometry, and the LUMO-HOMO energy gap to support the geometrical structure of the synthesized compounds. On the other side, the optical constants of H2ASB and its complexes have been studied over 300–1500 nm spectral range. The optical band gap (Eg) values of the present film's changes from 1.92 eV for H2ASB to 1.45 eV for CuHASB(5) film whereas the static index of refraction (n) takes a different behavior. The obtained values of n and Eg are the same as those recorded for many semiconductor materials. This means that, compared to the cost and ease of preparation, these films under study could replace many other semiconductors, such as CdTe with (Eg = 1.5 eV) which is the same value of CuHASB(4) film. With the help of n and extinction coefficient (k) values, the dielectric and non-linear optical parameters have been estimated and well discussed. Finally, the sheet resistance (Rs) and thermal emissivity (εth) changes due to the incident photon energy have been investigated. It was observed that, the change of Rs and εth with E is opposite to the change of other parameters such as the absorbance and optical conductivity.

Design, synthesize, physicochemical characterization, nonlinear optical properties structural elucidation, biomedical studies, and DNA interaction of some new mixed ligand complexes incorporating 4,6‐dimethylpyrimidine derivative and imidazole ligand

This study was planned to prepare new mixed ligand chelates derived from N‐(4,6‐dimethylpyrimidin‐2‐yl)‐3a,4,5,6,7,7a‐hexahydro‐1H‐benzimidazol‐2‐amine (BIP), and imidazole (I). They identified through CHN study, spectroscopic (NMR, FT‐IR, and UV–Vis), conductivity, magnetic susceptibility, mass analysis, and thermal analysis. Correlation between all results exposed that the BIP ligand performed as a bi‐dentate ligand through NN donation locations, where the co‐ligand shows as N–H monodentate. The optimization for the studied chelates led to the formation of distorted octahedral geometry for BIPICu and BIPIVO chelates, distorted (tetrahedral and square planar) geometry for BIPIAg and BIPIPd chelates, respectively, around the metal salt. The B3LYP level, B3LYP/6‐311G** level for the free ligand, and B3LYP/6–311G**‐LANL2DZ functional level for the solid chelates were used in density functional theory (DFT) calculations. The findings showed that DFT calculations produce conclusions that are consistent with those of the experiments. The resulting compounds' nonlinear optical properties were examined by calculating the hyperpolarizability (β) and molecular polarizability (α) parameters, which gave rise to several unexpected optical properties for the synthesized compounds. Using the agar well diffusion method, the antimicrobial activity of the produced compounds was experimentally confirmed against a subset of G+ and G− bacteria. To ascertain how these substances attach to the targeted protein binding sites, a molecular docking mechanism between the microbially resistant chelates and their suppressed microbial protein pocket receptors was investigated. Also, DNA binding estimated for studied structures was tested by electronic absorption spectrum, viscosity estimation, and gel electrophoresis. Data proposed that all tested compounds link with DNA using an intercalation, electrostatic, and covalent binding mechanism. Moreover, antioxidant performance for studied compounds was governed by radical scavenging techniques in vitro. In addition, an MTT assay has been worked out to explore in vitro cytotoxic impending. All the tested chelates assumed antimicrobial, antitumor, and antioxidant performances that cause them to suggest drugs.

A DFT and catalytic studies of recyclable chitosan based heterogeneous Cu(II) catalyst for the oxidation of tetralin

The oxidation of hydrocarbons is an essential transformation for converting petroleum-based raw material into useful chemicals like diols, epoxides, alcohols, and carbonyl compounds. In this context, a chitosan (Cs) based heterogeneous catalyst, {Cu(II)[Cs-L1-L2]Cl2} was developed by the coordination of two different Schiff base ligands, L1 [Cs-HACP] and L2 [ANI-HACP] with the chitosan and followed by complexation with CuCl2·2H2O The prepared catalyst {Cu(II)[Cs-L1-L2]Cl2} was characterized by different techniques such as Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET) surface area, Powder X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet visible near-infrared (UV–VIS-NIR), X-Ray photoelectron spectroscopy (XPS) and Density Functional Theory (DFT) studies. DFT studies suggest that {Cu(II)[Cs-L1-L2]Cl2} have octahedral geometry and +2 oxidation state of Copper is identified on the basis of XPS analysis. The Catalytic behavior of newly prepared heterogeneous catalyst {Cu(II)[Cs-L1-L2]Cl2} was studied for the tetralin oxidation using 70 % tert-butyl hydroperoxide [70 % TBHP]. Tetralin on oxidation gave 1-tetralol, 1-tetralone and some other products. A maximum conversion of 82.11 % tetralin with 10.42 % selectivity of 1-tetralol (T-lol) and 74.89 % selectivity of 1-tetralone (T-lone) was obtained after 5 h of reaction at 80 °C. The heterogeneous catalyst, {Cu(II)[Cs-L1-L2]Cl2}was easy to separate and recyclable. The catalyst was recycled seven times.

Green Light-Triggered Photocatalytic Anticancer Activity of Terpyridine-Based Ru(II) Photocatalysts.

The relentless increase in drug resistance of platinum-based chemotherapeutics has opened the scope for other new cancer therapies with novel mechanisms of action (MoA). Recently, photocatalytic cancer therapy, an intrusive catalytic treatment, is receiving significant interest due to its multitargeting cell death mechanism with high selectivity. Here, we report the synthesis and characterization of three photoresponsive Ru(II) complexes, viz., [Ru(ph-tpy)(bpy)Cl]PF6 (Ru1), [Ru(ph-tpy)(phen)Cl]PF6 (Ru2), and [Ru(ph-tpy)(aip)Cl]PF6 (Ru3), where, ph-tpy = 4'-phenyl-2,2':6',2″-terpyridine, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, and aip = 2-(anthracen-9-yl)-1H-imidazo[4,5-f][1,10] phenanthroline, showing photocatalytic anticancer activity. The X-ray crystal structures of Ru1 and Ru2 revealed a distorted octahedral geometry with a RuN5Cl core. The complexes showed an intense absorption band in the 440-600 nm range corresponding to the metal-to-ligand charge transfer (MLCT) that was further used to achieve the green light-induced photocatalytic anticancer effect. The mitochondria-targeting photostable complex Ru3 induced phototoxicity with IC50 and PI values of ca. 0.7 μM and 88, respectively, under white light irradiation and ca. 1.9 μM and 35 under green light irradiation against HeLa cells. The complexes (Ru1-Ru3) showed negligible dark cytotoxicity toward normal splenocytes (IC50s > 50 μM). The cell death mechanistic study revealed that Ru3 induced ROS-mediated apoptosis in HeLa cells via mitochondrial depolarization under white or green light exposure. Interestingly, Ru3 also acted as a highly potent catalyst for NADH photo-oxidation under green light. This NADH photo-oxidation process also contributed to the photocytotoxicity of the complexes. Overall, Ru3 presented multitargeting synergistic type I and type II photochemotherapeutic effects.

Comprehensive insights of a Salamo-like Oligo(N,O-donor) ligand and its self-assembled di-nuclear Mn(III) and tetra-nuclear Cd(II) complexes

The self-assembled di-nuclear Mn(III) & tetra-nuclear Cd(II) salamo-like oligo(N,O-donor) complexes, [Mn2(L)2(CH3OH)2]·4CH3OH (1) and [Cd4(L)2(η-OAc)2(CH3OH)2] (2) have been constructed successfully applying the measure of solvent evaporation and characterized structurally by X-ray diffraction analyses of single crystal, IR & UV visible analyses. The single crystals of the salamo-like oligo(N,O-donor) compound H3L have been obtained by wet-chemical technique, its established structure is H3L∙CH3OH. The structure of complex 1 is centrally symmetrical, and both Mn(III) atoms are hexa-coordination and have slightly distorted octahedral geometries. There are two sets of intermolecular H-bonding interactions which are connected with adjacent units of the Mn(III) complexes and form a two-dimensional network structure. For the complex 2, all of the Cd(II) atoms are also hexa-coordination and possess slightly twisted octahedral configurations. And five groups of intermolecular H-bonding interactions form a honeycomb shaped three-dimensional supramolecular structure. Additionally, the intermolecular interactions of H3L, complexes 1 and 2 have been quantified by Hirshfeld surface analysis for further study. Fluorescence emission spectra of H3L, complexes 1 and 2 were also investigated.

Luminescent Ln3+-based silsesquioxanes with a β-diketonate antenna ligand: toward the design of efficient temperature sensors.

We report the synthesis and single-crystal X-ray diffraction, magnetic, and luminescence measurements of a novel family of luminescent cage-like tetranuclear silsesquioxanes (PhSiO1.5)8(LnO1.5)4(O)(C5H8O2)6(EtOH)2(CH3CN)2⋅2CH3CN (where Ln = Tb, 1; Tb/Eu, 2; and Gd, 3), featuring seven-coordinated lanthanide ions arranged in a one-capped trigonal prism geometry. Compounds 1 and 2 exhibit characteristic Tb3+ and Tb3+/Eu3+-related emissions, respectively, sensitized by the chelating antenna acetylacetonate (acac) ligands upon excitation in the UV and visible spectral regions. Compound 3 is used to assess the energies of the triplet states of the acac ligand. For compound 1, theoretical calculations on the intramolecular energy transfer and multiphonon rates indicate a thermal balance between the 5D4 Stark components, while the mixed Tb3+/Eu3+ analog 2, with a Tb:Eu ratio of 3:1, showcases intra-cluster Tb3+-to-Eu3+ energy transfer, calculated theoretically as a function of temperature. By utilizing the intensity ratio between the 5D4→7F5 (Tb3+) and 5D0→7F2 (Eu3+) transitions in the range 11-373K, we demonstrate the realization of a ratiometric luminescent thermometer with compound 2, operating in the range 11-373K with a maximum relative sensitivity of 2.0% K-1 at 373K. These findings highlight the potential of cage-like silsesquioxanes as versatile materials for optical sensing-enabled applications.

Synthesis, Structure and Antiferromagnetic Large‐Distance Long‐Range Coupling of the Ruthenate(V) Sr3(Ag2/3Sr1/6)RuO6

AbstractBlack, air‐stable crystals of the new ruthenate(V) Sr3(Ag2/3Sr1/6)RuO6 were grown in a silver ampoule using KO2 as oxidative flux. X‐ray diffraction on single‐crystals revealed a rhombohedral structure with the space group R c. Sr3(Ag2/3Sr1/6)RuO6 crystallizes isostructural to Sr4PtO6 in the K4CdCl6 structure type. By sharing trigonal faces, alternating [RuO6] octahedra and [(Ag2/3Sr1/6□1/6)O6 trigonal prisms form segmented chains running parallel to the crystallographic c‐axis. Eightfold coordinated strontium cations are located between the rods. Regardless of the wide spatial separation of the magnetic cations (588 and 594 pm), Sr3(Ag2/3Sr1/6)RuO6 shows long‐range antiferromagnetic order below the relatively high Néel temperature of 79 K in magnetic fields up to at least 9 T, as measurements of the magnetic susceptibility and heat capacity show. Despite the pseudo one‐dimensional character of the structure, the characteristic of the susceptibility indicates a three‐dimensional coupling of magnetic ions.

Synthesis, Structure and Biological Activity Studies of New Metal Ion Complexes Based on 3-[(3-Hydroxynaphthalene-2-yl-ethylidene)-hydrazono]-1,3-dihydro-indol-2-one

In the present study, a novel ligand (L) made of 2-hydroxynaphthaldehyde and 3-hydrazone-1,3-dihydro-indole-2-one(3-[(3-hydroxynaphthalen-2-yl-ethylidene)-hydrazono]-1,3-dihydro-indol-2-one). The ligand was characterized by FTIR, UV-vis, mass, 1H-NMR, 13C-NMR, and CHN elemental analysis. New complexes of this ligand were created by treating methanol and a drop of DMF solution of the produced ligand with the hydrated metal salts of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) in a molar ratio of 2:1 (L:M). As a result, complexes have been emerged and identified FTIR, UV-vis, C.H.N., chloride-containing, molar conductance, magnetic susceptibility, and atomic absorption. The characterization result for each complex indicated complexes with octahedral coordination geometry and tridentates with metal to ligand ratios of 1:2. The biological activities of the new compounds were examined against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) giving an acceptable inhibition efficiency.

ICEMS Characterization of NixFe3-xO4 (0.7 ≤ x ≤ 1.7) thin films grown by ion beam sputtering on (0001) Al2O3 substrates

We report here on the ICEMS characterization of nickel ferrite (NixFe3−xO4) thin films having different nickel contents grown on alumina substrates by Ion Beam Sputtering. The spectra corresponding to the films with nominal x = 0.7, 1.0 and 1.2 are characteristic of compounds crystallizing in a spinel-related structure showing two different magnetic sextets associated with Fe3+ located in the tetrahedral and octahedral sites of such structure. The spectra show an additional broad third sextet with a large isomer shift which suggests the occurrence of electron hopping between Fe2+ and Fe3+ ions sitting in the octahedral sites. With increasing nickel content, the linewidth of the sextets increases and their corresponding hyperfine magnetic fields decrease. This is an indication of an increase in structural disorder in the deposited films as their nickel concentrations increase. The cation distribution of the iron ions over the tetrahedral and octahedral sites appears also to depend on the nickel content. The film with x = 1.2 shows a significant increase in the fraction of octahedral iron ions as compared with the expected nominal value suggesting that, for this composition, some Ni2+ could also occupy tetrahedral sites. The Mössbauer spectrum corresponding to the film with x = 1.7 shows a magnetic pattern with very broad lines similar to those shown by amorphous or disordered materials. The average isomer shift is quite high (around 0.40 mms− 1) and characteristic of Fe3+ in octahedral oxygen coordination. This indicates that for the largest nickel content studied (x = 1.7), the film does not contain Fe3+ in tetrahedral environments suggesting that the spinel structure is no longer present. This correlates well with the X-Ray Diffraction data which indicate a structural change from spinel to a disordered rock-salt structure for this particular film with high nickel content.

Syntheses and photochemically antibiotic degradation of two Co(II)-based coordination polymers

Two new Co(II)-based coordination polymers (CPs), designated as [Co2(bbp)4(1,3-bdc)4]n(1) and [Co(bbp)3(NO3)2(H2O)]n(2) (bbp = 3,5-bis(benzoimidazo-1-ly) pyridine; 1,3-H2bdc = 1,3-benzenedicarboxy acid), were synthesized using a dual ligand approach. The characterization of these CPs involved single- crystal -XRD, UV–visible, FT-IR, and TGA analysis. Both CPs 1 and 2 exhibit a distorted octahedral geometry. Both 1 and 2 show a 1D ladder chain, and this chain-like structure undergoes further development into a more intricate two-dimensional (2D) supramolecular network. The thermal stability analysis revealed that 1 and 2 are stable at temperatures of 119 °C and 286 °C, respectively, with no significant mass loss. Notably, both CPs displayed semiconducting properties. The photocatalytic degradation capabilities of CPs 1 and 2 were investigated against antibiotics such as metronidazole (MDZ), Tinidazole (TDZ), ornidazole (ODZ), and furazolidone (FZD). CP 1 exhibits exceptional photocatalytic activity against FZD. A dosage of 5 mg/L of CP 1 resulted in a remarkable degradation efficiency of 92.2 % for 40 ppm FZD. Additionally, a proposed photodegradation mechanism was investigated through radical trapping experiments.

Synthesis and Characterization of Biopotent Transition Metal Complexes of Schiff Base 2-{(1)-1-[2-(1,3-Benzothiazol-2-yl)hydrazinylidene]ethyl}-6,10b-dihydro-3H-benzo[f]chromen-3-one and their Biological Evaluation

Three transition metal(II) complexes (M = Co/ Zn/Pd) were synthesized by using a newly synthesized Schiff base ligand 2-{(1E)-1-[2-(1,3-benzothiazol-2-yl)hydrazinylidene]ethyl}-6,10b-dihydro-3H-benzo[f]chromen-3-one (L) by conventional method. The structure of the compounds were determined by physical and analytical techniques like UV-visible, FT-IR, 1H and 13C NMR and mass spectroscopic techniques and the crystallinity and inter-planar distance of the complexes were confirmed by XRD. The electron density in HOMO and LUMO was determined by DFT studies. The studies of electronic spectra and measurements of magnetic susceptibility suggest that Co(II) complex shows an octahedral geometry, Pd(II) complexes show square planar geometry and (ZnL2Cl2) complex shows tetrahedral geometry. The molar conductivity results suggested the non-electrolytic nature of the metal(II) complexes. The synthesized compounds was tested against antibacterial activity for Gram-positive and Gram-negative bacteria. The molecular docking study demonstrated that the ligand and its metal(II) complexes possess antibacterial and anticancer properties, and the results showed that the compounds were effective against the microorganisms that were examined. Furthermore, the results found that metal(II) complexes provided enhanced immunity against cancer cell lines.

Synthesis, structural characterization and bioactivities of iron(III) and copper(II) complexes containing Schiff base thiourea ligands of 5‐(tert‐butyl)‐2‐hydroxybenzaldehyde

AbstractAzomethine and thiourea groups possess potential bioactive functions in pharmacological substances so organic ligands containing both imine and thiourea groups and their metal complexes will be expected to have remarkable bioactivities. In this study, some iron(III) and copper(II) complexes containing Schiff base thiourea ligands derived from 1‐(2‐aminoethyl)‐3‐phenylthiourea or 1‐(2‐aminophenyl)‐3‐phenylthiourea and 5‐(tert‐butyl)‐2‐hydroxybenzaldehyde were synthesized and characterized by modern physicochemical analysis approaches such as mass, infrared, UV–vis spectra and effective magnetic moments. The analytical data have supported for the structures of iron(III) complexes in the molecular ratio of 1:2 of iron(III) and the relative ligand while copper(II) complexes in the ratio of 1:1. The synthetic ligands coordinated with iron(III) as NO bidentate mode, however they chelated with copper(II) as NNOS tetradentate possibly. The obtained iron(III) complexes possess high‐spin octahedral geometry when copper(II) complexes perform distorted square planar. The obtained metal complexes were investigated in their thermal stability and chemical components by the thermogravimetric analysis. The synthetic Schiff base thiourea ligands were examined for their antimicrobial activity. Additionally, the synthesized complexes were estimated for their in vitro anticancer property against human cancer cell lines, hepatic cancer cells (HepG‐2), and lung adenocarcinoma cells (A549).